Tire pressure monitoring (“TPM”) systems are known in the art. TPM systems include a tire condition sensor which may be located within the tire for monitoring tire conditions such as tire pressure and temperature. The sensor includes an associated transmitter for transmitting a radio frequency (“RF”) signal indicative of the sensed tire condition. As part of the transmitted signal from the sensor, a unique sensor identification is provided. Each sensor of a TPM system has an associated, unique sensor identification code. The TPM system further includes a receiver for receiving the sensor signals and for controlling a display within the vehicle cabin to indicate to the vehicle operator the condition of the vehicle tires. For the receiver to display tire information for a particular tire location on the vehicle, the receiver must be programmed to match the sensor identification with its associated tire location. Whenever tires are rotated or sensors replaced, the receiver must be reprogrammed to “learn” the sensor identification at each tire location.
TPM systems have been proposed that include interrogators at each tire location. Each interrogator sends an interrogation signal to its associated TPM sensor. The sensors respond and transmit its sensor ID so that the receiver can match the ID with the tire location. One proposed system uses low frequency (“LF”) interrogators to provide a short range LF signal that is received only by the sensor associated with that LF interrogator.
Having a LF interrogator for each associated tire location adds to the cost of the TPM system.